Frederick Law Olmsted, journalist, social critic, landscape architect, and city planner, was born on April 26, 1822, in Hartford, Connecticut. Olmsted originally pursued a career as a scientific farmer, but like so many of his contemporaries he migrated to New York City and found opportunity in the metropolis. In the 1850s he made two journeys through the American South and published his observations in the New-York Daily Times and the New York Daily Tribune. Olmsted later reshaped these columns into his well-known books, A Journey in the Seaboard Slave States (1856), A Journey through Texas (1857), and A Journey in the Back Country (1860), invaluable contemporaneous accounts that portrayed the decivilizing effects of slavery on Southern society. A fourth volume, The Cotton Kingdom (1861), was largely abridged from the earlier books: in the new introduction Olmsted promoted free labor over slave and argued once again that slavery impeded the development of a civilized society in the South. During the mid-1850s Olmsted also became a partner in a New York publishing venture, Dix and Edwards, and worked as managing editor of Putnam's Monthly Magazine. While Olmsted gained an international reputation for his writings on slavery, the collapse of Dix and Edwards during the Panic of 1857 left him without a job and deep in debt.

A chance meeting with a member of New York City's new Central Park Commission in August 1857 led Olmsted to apply for the position of superintendent of laborers on the park, and following his appointment to the park he collaborated with architect Calvert Vaux in preparing the “Greensward” plan, which captured first premium in the competition to determine the park's design. Named architect-in-chief and superintendent in May 1858, Olmsted, over the next twelve years, oversaw construction of the park, a massive public works project that employed as many as 3,800 workers to transform 843 deforested and scarred acres (341 ha) into a seemingly natural landscape. Olmsted and Vaux gave the park its most distinctive landscape features, especially the breadth of scenery across meadows and lakes, as well as an ingenious system that separated pedestrians from horseback and carriage routes and placed crosstown traffic in sunken transverse roads. Olmsted also supervised the public's use of the park and organized and trained a corps of park keepers to educate visitors in the proper use of this new democratic institution.

Following the outbreak of the Civil War, Olmsted became secretary and chief executive of the U.S. Sanitary Commission, a privately funded organization that oversaw army camps, promoted the health of the Union forces, and cared for the wounded. In this capacity Olmsted brought the formidable organizational skills he had developed at Central Park to coordinating relief activities from all Northern states and fighting to modernize medical care in the army. Exhausted after two years of stressful work and intense political battles, in 1863 he accepted a position as head of the Mariposa Company, a gold-mining venture in California. There Olmsted encountered the beauty of the Yosemite Valley and the Mariposa sequoia grove, which he helped preserve as a state reservation; there too he began writing a lengthy inquiry into the impact of emigration and the frontier on social conditions and institutions in the United States. Surviving manuscript pages present Olmsted's penetrating analysis of the battle between the forces of barbarism and civilization in America.

With the failure of the Mariposa Company in 1865, Olmsted again faced an uncertain future. At Vaux's urging he returned to New York to collaborate on the preparation of a plan for Prospect Park in Brooklyn and to accept appointment as landscape architects to the Central Park Commission. Although Olmsted took an active role in editing The Nation, E. L. Godkin's weekly journal of politics and culture, after the Civil War he found his calling as a landscape architect and planner.

In Prospect Park, Olmsted and Vaux created a remarkably beautiful landscape that gave the visitor a “sense of enlarged freedom,” a temporary escape from the crowding and congestion that otherwise characterized the city. The Long Meadow, a sweeping lawn, visually endless in extent, promoted what Olmsted termed an “unbending of the faculties,” a therapeutic process of recuperation from the stresses of urban life. In their plans for the Brooklyn Park Commission, Olmsted and Vaux incorporated two parkways, Eastern and Ocean, which were two hundred feet (61 m) wide, providing space for a central carriage drive, service roads, and pedestrian paths, all separated by rows of trees. The parkway, they believed, was more than a handsome approach drive; it extended the benefits of the park to distant neighborhoods and provided the spine for openly built residential blocks.

In 1868 Olmsted developed a new form for the expanding American metropolis. In that year he sketched the outlines of a comprehensive park system for Buffalo, New York. Olmsted not only chose the site of Delaware Park but also sketched plans for two other parks: the Front, a thirty-two-acre (13-ha) tract adjacent to the Niagara River; and the parade, a fifty-six-acre (23-ha) park on the eastern side of the city, linked as a system by a series of parkways. These smaller parks would provide active recreation areas, playgrounds, and spaces for civic festivals—uses that Olmsted considered important to residents of a city but inappropriate for the large park. During the same year Olmsted also visited Chicago to advise the Riverside Improvement Company on the design of a new suburban community nine miles (14 km) west of the city. Olmsted's design for Riverside incorporated the curvilinear streets and landscape elements similar to the parks, although he emphasized the domestic scale of the suburb and the importance of the well-designed household. It also included a park along the Des Plaines River, which passes through the community, and a series of linked spaces he named the Long Common, as well as a parkway that extended from Riverside to Chicago. Riverside exemplified Olmsted's conceptualization of the suburb not as an escape from the city but as an essential part of the process of metropolitan growth.

Over the next twenty-seven years, until his retirement in 1895, Olmsted was the most prolific landscape architect in the United States. He and his firm planned major parks and park systems for more than twenty cities, fifty suburbs and communities, fifty-five college campuses and institutional grounds, and hundreds of private estates. Notable works include the grounds of the U.S. Capitol in Washington, the Boston park system, the Stanford University campus, and the site of the World's Columbian Exhibition in Chicago. Olmsted also played a crucial role in the preservation of the Niagara Reservation as the first state park in the nation. In these works Olmsted helped establish the profession of landscape architecture in the United States and trained many of the individuals who would guide its evolution in the twentieth century.

Deeply committed to what he considered a more civilized cityscape, Olmsted denounced the gridiron street system as a relic of an earlier stage of urbanization. In his numerous designs Olmsted attempted to create alternatives to the density, congestion, and incessant pace of urban life. He envisioned a metropolis as a house with many rooms serving different functions—one that would include a compact business district, to be sure, as well as openly built residential neighborhoods, spacious, naturalistic parks, and suburbs. His landscapes attempted to create a humane and humanly scaled city. As Charles Beveridge has noted, uniting all of Olmsted's works was his desire to use landscape art to meet deep human needs. Olmsted died in Waverly, Massachusetts, on August 28, 1903.